Hemoglobin gives up O2 when
- A. carbon dioxide concentrations are high
- B. body temperature is lowered.
- C. pH values are high
- D. CO2 concentrations are low
Correct Answer: A
Rationale: The correct answer is A: carbon dioxide concentrations are high. When carbon dioxide levels are high, it leads to a decrease in blood pH, triggering hemoglobin to release oxygen more readily through the Bohr effect. This is a physiological response to maintain homeostasis. The other choices (B, C, D) do not directly affect the release of oxygen from hemoglobin.
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Each of the following factors affects the rate of external respiration except the
- A. PO2 of the alveoli
- B. PCO2 of the blood
- C. thickness of the respiratory membrane
- D. PN2 of the alveoli
Correct Answer: D
Rationale: The correct answer is D: PN2 of the alveoli. The rate of external respiration is primarily influenced by the partial pressure of oxygen (PO2) in the alveoli, as it drives oxygen diffusion into the blood. PCO2 affects the removal of carbon dioxide. The thickness of the respiratory membrane impacts gas exchange efficiency. However, PN2 does not significantly impact gas exchange in the lungs, as nitrogen (N2) is inert and does not participate in gas exchange. Thus, PN2 of the alveoli does not affect the rate of external respiration.
The nurse is assessing a patient who frequently coughs after eating or drinking. How should the nurse best follow up this assessment finding?
- A. Obtain a sputum sample.
- B. Perform a swallowing assessment.
- C. Inspect the patient's tongue and mouth.
- D. Assess the patient's nutritional status.
Correct Answer: B
Rationale: The correct answer is B: Perform a swallowing assessment. This is the best follow-up because coughing after eating or drinking can be a sign of dysphagia, a swallowing disorder. By performing a swallowing assessment, the nurse can identify any issues with the patient's ability to swallow safely, which can lead to aspiration and respiratory complications. Obtaining a sputum sample (A) may not provide relevant information in this context. Inspecting the patient's tongue and mouth (C) may not directly address the coughing after eating. Assessing the patient's nutritional status (D) is important but may not address the immediate issue of coughing after eating or drinking.
Which of the following substances is activated by passage through the pulmonary circulation?
- A. Bradykinin
- B. Serotonin
- C. Noradrenaline
- D. Angiotensin 1
Correct Answer: D
Rationale: The correct answer is D: Angiotensin 1. When blood passes through the pulmonary circulation, angiotensinogen is converted into angiotensin 1 by the enzyme renin. This activation occurs in the lungs. Bradykinin, serotonin, and noradrenaline are not activated in the pulmonary circulation. Bradykinin is a peptide released during inflammation, serotonin is a neurotransmitter, and noradrenaline is a neurotransmitter and hormone. Therefore, D is the only substance activated by passage through the pulmonary circulation.
Vital capacity of lungs of an average human is
- A. 3000-4500 ml
- B. 1500-1800 ml
- C. 2000-2500 ml
- D. 500-1000 ml
Correct Answer: A
Rationale: The vital capacity of lungs is the maximum amount of air a person can exhale after a maximum inhalation. The average vital capacity for an adult human is typically between 3000-4500 ml. This range allows for efficient gas exchange in the lungs. Choice B (1500-1800 ml) and Choice C (2000-2500 ml) fall below the average vital capacity, indicating limited lung capacity. Choice D (500-1000 ml) is significantly low and would not support normal respiratory function. Therefore, Choice A (3000-4500 ml) is the correct answer as it aligns with the average vital capacity range for an average human.
A nurse is caring for a male client with emphysema who is receiving oxygen. The nurse assesses the oxygen flow rate to ensure that it does not exceed:
- A. 1 L/min
- B. 2 L/min
- C. 6 L/min
- D. 10 L/min
Correct Answer: B
Rationale: The correct answer is B: 2 L/min. The rationale is that in emphysema, high oxygen flow rates can cause oxygen toxicity. The recommended maximum flow rate for patients with emphysema is typically 2 L/min to prevent oxygen toxicity. Choice A (1 L/min) may not provide sufficient oxygen, choice C (6 L/min) and choice D (10 L/min) are too high and can lead to oxygen toxicity in patients with emphysema. Therefore, choice B is the most appropriate and safe option for this client.